In this work, we have applied a linear response approach to determine the \(\alpha _d\) , \(\alpha _q\)  and \(B\)  values of Zn in the relativistic CC (RCC) theory framework by retaining the spherical symmetry properties of atoms. Earlier, we had employed this approach to determine \(\alpha _d\)  of Zn using the expectation value approach of the RCC theory [1]}. This approach involves a non-terminating series and contribution from the normalization of the wave function was not included in order to conveniently evaluate the expression by making use of the connecting terms. However, two different implementations of this method had produced quite different \(\alpha _d\)  results for the Cd atom [1]}, [3]}. To avoid brute-force termination in the expression and ambiguity in accounting for the contribution from the normalization of the wave function, we have developed the relativistic normal coupled-cluster (RNCC) theory to determine the aforementioned quantities [4]}. The RNCC method has been applied previously for the accurate determination of \(\alpha _d\)  values for Xe, Cd and Hg atoms [4]}, [6]}, [7]}, resulting in a reconciliation between the theoretical and experimental polarizability values for the Cd atom [6]}. This immediately prompted a re-analysis of the experimental data for this atom [9]}. A recent calculation of \(\alpha _d\)  of Cd using the finite-field approach in the RCC theory framework offers further support to these findings [10]}. In view of this, it is imperative to carry out the polarizability calculations of Zn using the RNCC theory and make a comparative analysis with the calculation obtained using the expectation value approach of the RCC theory to understand better about both the methods. In this work, we have performed calculations of \(\alpha _d\) , \(\alpha _q\)  and \(B\)  using expectation value approach in the RCC and RNCC methods. We then compare results from both the approaches term-by-term. In addition, we give results from a lower-order method using the same basis functions in order to demonstrate the propagation of electron correlation effects at different levels of approximations in the many-body method. The results are given in atomic units (a.u.) unless otherwise stated explicitly.
